Hypothyroidism, or underactive thyroid gland, is a disease that affects the thyroid gland. It is a condition in which the thyroid gland does not produce enough thyroid hormones to be released into the blood stream. This could be due to an autoimmune disease called Hashimoto’s disease, congenital absence of the gland or from surgical removal of the thyroid gland. Underactive thyroid gland can lead to defunct in normal metabolic activities of the body.
What is the Thyroid Gland?
The thyroid gland is a h-shaped or butterfly shaped endocrine gland located in the lower part of the front of the neck. This gland produces and secretes two major thyroid hormones called thyroxine (T4) and triiodothyronine (T3), whose major function is to increase the body’s metabolism thereby increasing the functional activity throughout the body, according to the body’s needs.
Some the functional activity includes:
- Increasing cellular metabolic activity.
- Has general and specific effect on growth.
- It stimulates fat metabolism thereby decreasing fat stores in the body.
- Increases heart strength.
- For a normal sexual function thyroid hormone needs to be normal in the body.
- Decreases the concentration of cholesterol.
Generally, the human body is programmed to always balance itself automatically, knowing when to increase or decrease production or release of any substance in order to prevent an over or under secretion. For the thyroid gland, thyroid hormone is controlled by the pituitary gland located in the brain, which secretes a hormone called thyroid stimulating hormone (TSH). This thyroid stimulating hormone directs the thyroid gland on when to increase or decrease secretion of the thyroid hormones. So hypothyroidism can also occur when there is a defect in this control system.
How Can I Tell If I Have Hypothyroidism?
Because the functions of the thyroid hormone are plenty and affects almost all part of the body, the symptoms of hypothyroidism are non-specific and so variable. The only way to know for sure is with a simple blood test for thyroid stimulating hormone. But some of the symptoms often include;
- Tiredness, weakness.
- Dry skin.
- Unable to tolerate cold temperatures.
- Hair loss.
- Difficulty concentrating and poor memory.
- Weight gain and poor appetite.
- Hoarse voice.
- Abnormally heavy or prolonged menstruation.
- Abnormally light or infrequent menstruation or absence or suppression of normal menstrual flow.
- Impaired hearing.
- Abnormal skin sensations such as tingling, numbness.
- Noticing changes in your face such as drooping eyelids, and puffiness in the eyes and face.
It is important to visit the hospital when you notice any of these symptoms. If diagnosed with hypothyroidism, also inform your family members because it is a disease that runs in the family.
So, What Causes This Condition?
There are lots of reasons why the thyroid gland becomes underactive and secretes a lower than normal amount of thyroid hormone into the blood stream. Some of these known causes are;
- Autoimmune disease – in this case, the body’s immune system that protects it against danger from foreign bodies, attacks the thyroid gland and destroys it. This leaves the thyroid gland unable to produce thyroid hormones. The most common is called Hashimoto’s disease. This Hashimoto’s disease is more common to women than men.
- Congenital hypothyroidism – This occurs when babies are born without a thyroid gland or an underdeveloped thyroid gland. This causes the thyroid gland cells to not be able to meet the body’s demands to produce enough thyroid hormone.
- Surgical removal of part or all of the thyroid gland – some people who have had to remove their thyroid gland in cases like Grave’s disease or thyroid cancer will definitely become hypothyroid.
- Certain Drugs – drugs such as amiodarone, lithium, interferon alpha, and interleukin-2 can prevent production of thyroid hormones by the thyroid gland.
- Iodine supply – too much or too little supply of iodine to the thyroid gland can cause hypothyroidism. Iodine is required for the production of thyroid hormones and if too little iodine is present in the body for these production, then it can cause enlargement of the thyroid gland called goiter. Surprisingly too much iodine can also cause hypothyroidism. So iodine has to be the right amount to prevent hypothyroidism.
- Thyroiditis – is an inflammation of the thyroid gland usually caused by an autoimmune attack. This causes a progressive deterioration of the thyroid gland until its unable to produce thyroid hormones.
- Idiopathic non-toxic goiter – in this case, goiter (enlargement of the thyroid gland) can occur in patients not deficient of iodine. Doctors call it idiopathic because the cause is unknown.
- Damage to pituitary gland – the pituitary gland produces a hormone called thyroid stimulating hormone that controls the secretion of thyroid hormone. Any damage to it, either by a tumor, radiation or surgery will dampen its effect in the thyroid gland which can lead to hypothyroidism.
Diagnosis of Hypothyroidism
Diagnosing hypothyroidism can be difficult as the symptoms can easily be confused with other conditions. A proper diagnosis of hypothyroidism depends on your medical and family history; where you tell your doctor about:
- Symptoms you have been experiencing.
- If you’ve had any surgery on your thyroid.
- If you’re taking any drugs that can cause hypothyroidism.
- And if any of your family members have thyroid disease.
- Physical examination; where the doctor checks your thyroid gland and looks for changes, the doctor also checks for other physical changes such as dry skin, swelling, slower reflexes and slower heart rates.
- Blood tests such as thyroid stimulating hormone (TSH) test and T4 test
- Thyroid stimulating hormone (TSH) test; is a common and important blood test for hypothyroidism. It measures how much thyroid hormone T4 the thyroid gland is being asked to make by checking the amount of thyroid stimulating hormone (TSH) being circulated in the blood. Abnormally high levels of TSH means the thyroid gland is asked to make more T4 as there isn’t enough T4 in the blood.
- T4 tests; measures the level of T4 in the blood. Too little amount tells that the patient has hypothyroidism.
Management and Prevention
Hypothyroidism can’t be cured but can be managed. The condition is treated by increasing the level of thyroid hormone which your thyroid gland is no longer able to make, thereby bringing the level back to normal. Your doctor will use medications to do that. One medication that can do this is levothyroxine. With proper management and attention to medication, patients with hypothyroidism can lead a normal and healthy life.
However, hypothyroidism can be life threatening and serious if left untreated. So when you notice any of the above symptoms, you should consult a medical practitioner or else your condition can lead to complications like:
- Developing mental health issues.
- Having heart problems.
- Developing goiter.
- And if you overdose on your drugs dosage, it can lead to hyperthyroidism, whose symptoms include inability to sleep, increase in heart rate, weakness in muscle etc.
In conclusion, it is uncertain about preventing hypothyroidism. But people who notice the above said symptoms should seek medical consultation especially people who are at risk of getting the disease like pregnant women. Your doctor can manage the condition to enable you live healthy life if you follow the doctor’s orders.
- Guyton and Hall textbook of Medical Physiology thirteenth edition, John E. Hall.
- American Thyroid Association
- Harrison’s Principles of Internal Medicine, by Jameson, Fauci, Kasper, Hauser, Longo, Loscalzo.